Rheumatoid arthritis (RA) is a debilitating and progressive disease that affects 1-2 percent of US adults and leads to chronic pain, loss of function, disability, loss of employment, and increased mortality. Currently, a cure for RA does not exist. Ultimate goals in managing RA are to prevent or control joint damage, prevent loss of function, and decrease pain. Achieving these goals requires early diagnosis and prompt initiation of aggressive treatment. In the past 5 years, treatment of RA has changed dramatically. The introduction of anti-TNF agents (biologies), which are powerful in action though very costly, can dramatically reduce disease progression; when biologies are not used, now combinations of potent new DMARDS (disease modifying anti-rheumatic drugs) are used to aggressively halt inflammation. However, currently we know very little about adherence to new RA therapies, especially biologies and combinations of more potent DMARDS. Thus, assessing and predicting adherence, and understanding common moderating factors is essential to clinical practice and research on determinants of treatment outcomes and efforts to improve patient adherence. The goals of this research proposal are to: (1) rigorously evaluate adherence to current RA therapies overtime in a cohort of patients; (2) relate adherence to disease activity and health outcomes; and (3) explore potential effect modifiers on the relationship between adherence and outcomes. We hypothesize that adherence to therapy is suboptimal, and will vary in relation to treatment (i.e., biologies vs. DMARDS), disease (i.e., burden/severity, previous use of DMARDS) and patient characteristics (depression status, demographics). Adherence will be associated with clinical and radiographic outcomes and health status at 1 yr. Depression will be associated with increased non-adherence. To test these hypotheses, we will utilize a one year observational study of 200 RA patients seen in the Johns Hopkins Arthritis Center.